Enzyme catalyzed hydroxymethylation of aromatic aldehydes with formaldehyde. Synthesis of hydroxyacetophenones and (S)-benzoins

Demir, Ayhan Sıtkı
Ayhan, P
Igdir, AC
Duygu, AN
Benzaldehyde lyase from the Pseudomonas Fluorescens catalyzed reaction of aromatic aldehydes with formaldehyde providing 2-hydroxy-1-arylethan-1-one in high yields via an acyloin linkage. Kinetic resolution of rac-benzoins with formaldehyde providing (S)-benzoins and 2-hydroxy-1-arylethan-1-one via C-C bond cleavage and a bond formation reaction.


Divergent synthesis of polysubstituted isoxazoles, isoxazoline N-oxides, and dihydroisoxazoles by a one-pot cascade reaction
Rouf, Abdul; ŞAHİN, Ertan; Tanyeli, Cihangir (Elsevier BV, 2017-01-26)
An efficient one-pot synthesis of a new class of 3,4,5-trisubstituted isoxazoline N-oxides/isoxazoles and dihydroisoxazoles is developed by a green approach from aromatic and aliphatic aldehydes by controlling the reaction conditions. Aldehydes were reacted with ethyl nitroacetate in the presence of DABCO as a catalyst under ultrasonication. In aromatic aldehydes, isoxazoline N-oxides were obtained exclusively when the reaction was carried out at 40 degrees C, but raising the temperature to 80 degrees C iso...
Reinvestigation of the synthetic and mechanistic aspects of Mn(III) acetate mediated oxidation of enones
Demir, Ayhan Sıtkı; Reis, O; Igdir, AC (Elsevier BV, 2004-04-05)
Mn(OAc)(3) mediated alpha'-acetoxylation of alpha,beta-unsaturated enones is reinvestigated from a synthetic and mechanistic point of view and an improved procedure based on the use of acetic acid as a co-solvent is presented. Excellent results were obtained for a variety of structurally diverse and synthetically important enones under the optimized conditions.
Zinc perchlorate catalyzed one-pot amination-annulation of alpha-cyanomethyl-beta-ketoesters in water. Regioselective synthesis of 2-aminopyrrole-4-carboxylates
Demir, Ayhan Sıtkı; Emrullahoglu, M (Elsevier BV, 2006-02-13)
In this paper, we report the efficient and regioselective synthesis of 2-aminopyrrole-4-carboxylates as derivatives of conformationally restricted analogues of gamma-amino butyrates (GABA) via a zinc perchlorate catalyzed amination-annulation of alpha-cyanomethyl-beta-ketoesters under mild reaction conditions in water.
Synthesis of thio- and furan-fused heterocycles: furopyranone, furopyrrolone, and thienopyrrolone derivatives
ERGUN, Merve; Dengiz, Çağatay; OZER, Merve Sinem; ŞAHİN, Ertan; BALCI, METİN (Elsevier BV, 2014-09-02)
We report herein the synthesis of a novel class of compounds, ethyl 4-oxo-4H-furo[3,2-c]pyran-6-yl carbonate, (7E)-7-[(dimethylamino)methylene]-4H-furo[3,2-c]pyran-4,6(7H)-dione, 5-oxo-N-phenyl-2,5-dihydro-4H-furo[3,2-b]pyrrole-4-carboxamide,and 5-oxo-N-phenyl-5,6-dihydro-4H-thieno[3,2-b] pyrrole-4-carboxamide starting from the corresponding acid derivatives. Intramolecular cyclization in the presence of thionyl chloride formed the target fused ring systems. Additional transformation was seen in the cycliza...
Asymmetric aldol addition of alpha-azido ketones to ethyl pyruvate mediated by a cinchona-based bifunctional urea catalyst
Okumus, Seda; Tanyeli, Cihangir; Demir, Ayhan Sıtkı (Elsevier BV, 2014-07-30)
The first asymmetric synthesis of ethyl 4-aryl-3-azido-2-hydroxy-2-methyl-4-oxobutanoates via a cinchona organocatalyst induced aldol addition of alpha-azido ketones to ethyl pyruvate has been developed. The coupling reaction under optimized conditions was carried out to furnish tetrafunctionalized synthons with enantioselectivities of up to 91:9 and enriched diastereoselectivities of up to 95:5 (syn:anti).
Citation Formats
A. S. Demir, P. Ayhan, A. Igdir, and A. Duygu, “Enzyme catalyzed hydroxymethylation of aromatic aldehydes with formaldehyde. Synthesis of hydroxyacetophenones and (S)-benzoins,” TETRAHEDRON, pp. 6509–6512, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/56111.